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T. A. EDISON. Apparatus for Electric Lights.

No. 218,167. Patented Aug. 5; 1879.

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UNITED STATES PATENT OEEIeE.

THOMAS A. EDISON, OF MENLO PARK, NEIV JERSEY.

llVlPROVEMENT lN APPARATUS FOR ELECTRIC LlGHTS.

Specification forming part ofLetters Patent No. 213,167, dated August 5,1879; application tiled January 10, 1879.

To all 107mm it may concern:

Be it known that I, THOMAS A. EDISON, of Menlo Park, in the State of NewJersey, have invented an Improvement in Apparatus for Electric Lights,of which the following is a specification.

It is well known that an electric current passed through a secondarybattery is stored up or reacts alter the original current ceases, sothat it can be used as a source of electricity.

I employ two secondary batteries, such as those known as the Plantebatteries. One of these is connected in the main circuit, and the samebecomes charged. A circuit-changer is introduced in the circuits in sucha manner as to connect this charged battery with one or more electriclights, and simultaneously throw the main circuit through the other secondary battery, to charge the same, after which that is connected withthe electric lights, and the main circuit reconnected to the firstsecondary battery, and so on.

In the annexed diagram, Figure 1, the circuit-coiniections areillustrated, and Fig. 2 is a perspective view of the switch. Fig. 3 is aside view of the secondary batteries.

The secondary batteries A B are of any desired construction. I prefer,and use, two sheets of lead wound together into a square or cylindricalform, and immersed in aeidulated water in a closed case.

The main line a. is connected with any.

lllflgliOiWGlGClTllC machine or other source of electric energy, and l)is the return-line or earth-collnection.

The mainline a is connected by the wires 0 to the seeoinlary batteries AI and the return-wires (l 0 pass through the switch f and wire 1 to Theelectric lamps g are represented in insulated disks (3 and 7respectively, against the peripheries of which the springs of i it rest,and this switch can be rotated periodically by a handle or by aclock-work or other suit-able means.

When the switch f is in one position the main circuit is closed througha, 0, A, (l, 4, 6, and i to l), and the secondary circuit is closed fromB through 71 lamps g, wire It, switch 7 5, and wire 0 to XVhen theswitch f is in the other position the main circuit from a passes by c toB, and by c, 4, 6, and l to b, while the secondary circuit from A is byit through lamps g, wire L 7 5, and wire (I to A, so that when thesecondary battery B is furnishing the accumulated electricity to thelamps g the main current is charging the secondary battery A, and viceversa.

The switch 1" may be actuated periodically by clock-work or any suitablemechanism.

When a secondary battery is fully charged, the decomposition of theliquid commences and gases are developed. I avail of this to actuate acircuit-regulator and disconnect the main current.

The two closed cases in which the secondary batteries are placed areprovided with tubes 8, passing to a chamber, 1', beneath a flexiblediaphragm, t; and in the metallic cir cuit a there is a switch or lever,a, that is acted upon to break the electric circuit to the secondarybatteries when the gases have accumulated sufiieient pressure to movesaid diaphragm.

The accumulated gases combine, and in so doing maintain the electricaction of the secondary batteries, and the pressure decreases, and thecircuit is again closed by the lover a.

I am aware that gas has been produced by an electric current decomposinga liquid, and that the confined gas has been employed to move electrodesand regulate the main current.

I claim as my invention 1. The combination, with electric lamps and amain circuit, of two secondary batteries and circuit-coimections andswitch, substan tially as set forth, to alternately change the main andsecondary circuits, substantially as ver in the main circuit,substantially as and specified. for the purpose specified. 1 2. Thesecondary circuit, containing electric Signed by me this 31st day ofDecember,

lamps, and the secondary battery and inclos- A. D. 1878.

ing-case, in combination with the main cir- THOMAS A. EDISON. cuitthrough the secondary battery, a dia- Witnesses:

phragm acted upon by the accumulation of WM. CARMAN,

gas in the secondary battery, and a switch-le- BENJ. D. AGKER.

